PAGES news, vol 5, no. 1 - PEP I

EWS OF THE INTERNATIONAL PALEOSCIENCE COMMUNIIY CORE PROJECT OF THE INTERNATIONAL GEOSPHERE-BIOSPHERE PROGRAMME IGBP

PEP

ffi mffiM

I

T I his is the first of the new-

syle PAGES Newsletters. lt :

rreedr itöi:'räspotd iro iäfleißr 'oür, the chonge in the orientotion

of PAGES from octivities concerned moinly with Agendo-setting, lowords on increosing emphosis on the implementotion of PAGES reseorch, ln the present Newsletter, we hove emphosized in different

woys, the octivities going on within two of the thröe PEP (PoleEquotor-Pole) Tronsects.

\\6 hwe

slso introduced two

exomples of developments in Volcanos, ice cores, Inke sediments, peat bogs and treerings: Volcano Parinacota and Laguna Chungara in the Chilean Altiplano are illustrating the aariety of paleo-archiues aasilable within the PEP I Transect.

(Foto:

M. Grosjean,Dept.

l

of Ceography,Unioersity of Bern, Switzerland).

to convene the first

"lnterhemispheric Poleoclimotes of fte Americos" meeting is loking shope.

The meeting

will be held in Merida,

notionol groups ond reseorch coniortior :lo,r,s,üb*,il,.mOteiiol.,:,.

.

revised ond updoted PAGESPANASH qnd PEP I portion of the PAGES Series 95-l is now qvoiloble from the coordinator, Vera Markgraf,

- Last 2000 Years Climate Variability,

tabase, previously published

- Mid Holocene

Climate Optimum/

Neoglacial, - Late-Glacial Climate Variability, - Last Glacial Maximum.

Coordinators of each topic session will provide a state-of-the-art interhemispheric synopsis, which is followed by specific comparative presentations from the marine and terreshial realm, address-

ing interhemispheric linkages.

Presentations will be published subsequently in a book.

I' '.

for inclusion in future issues.

The Sponish tronslqtion of the

Modern Climate Variability, - El Niflo/Southern Oscillation, -

as

a

Paleoclimatology Publication Series Report No. 4,7996, (V. Markgraf, L.Anderson, J. Keltner, E. Grimm "The Latin American Pollen Database Site Inventory", World Data Center-Afor Paleoclimatology, NOAA Paleoclimatology Program, Boulder, Colorado, 80303). This inventory, which is also available on the VWVWeb (http: I lwww.ngdc.nona.goo lpaleo I paleolhtml)hsts all reported sites of pollen

records in LatinAmerica, including geo-

graphic information, radiocarbon chronology, age of record, and publication.

Workshop Reports lnside PAGES Notionol Activities oround the World PAGES Cqlendor PAGES Scientific Highlight: Greot Borrier Reef 'Climqlic Optimum' ot 5,800 Y BP {M.

lll;r;i.;,ii;;r;,i.il; issues of the Newsletier per

yeor, os before ond we olso plon to retoin the moin components of previous Newslel*'ers - Workshop Reports, the illustroted, scienfi

fic'PAGES Highlighf,

short discussion odicles, personol news of the PAGES community ond the Colendor.

The success of oll these

depends on input from reoders os much os on the efforts of the Proiect Office

ond editoriol stoff.

The next newslefrer should

contoin detoils of develop ments in PEP lll, os well os o moior section devoted to the .!,m[ies5ival,eoi$1,iüicesler, ol,, the IMAGES progromme. We sholl emphosize short, welL

illustroted summories of 'highlights' wherever possible.

PEP I Reseqrch ond Workshop Activities PEP ll Activities in New Zeolqnd, Ghinq qnd Tqiwon

The oim is to introduce the

strength ond flovour of the science in the best ond briefest woy possibh, not to turn the Newsletter into o vehicle for 'grey' publicotions.

K. Gogon et ol.)

I

thot this will encouroge other

upon request (PAGES Series 96- 6). Copies were distributed at the II Southern Connection Meeting in Valdivia, January 6 through 71,1997. This version also includes the revised and updated site inventory of the Latin American Pollen Da-

Venezuela, March 1998.

The following topics, to be organized by coordinators, will be discussed:

iesmiih' :r&rd i;aiodr,

ot notionol level, in the hope

COORDINATION NEWS . Ihe plon

PAGE5,,

FneNr OiorrrLo

PEP I PAGES

.

PEP CONTINENTAT

DRIIIING

ffi*"*i:il"T:::?ä'.'ä*i'J,',:i:

EFFORTS L" Ä.hsliarg

number of long, continuous paleoclimate records from the deep sea and polar ice caps. Comparable long paleoclimate records from the continents, on the other hand, are relatively scarce, despite the fact that they are unique in providing insight into how global and regional climates influence the biosphere upon which humanity is most intimately dependent (see figure of sites with existing and proposed long records along the PEP I transect). To promote and develop a

is based on the great

I-ake

Tulc lxke

0t1 ,Great $ait L*ke

l?i?

Pyramid Lake Clear l-*ke

r

San Agustie Flains

l,ake Cuenca deMesicoS

L. ChaPala

framework for long continental records a PAGES workshop entitled "Continental Drill-

'

uts

3:r.

L,Nica

ing for Paleoclimate Records" was convened in Potsdam in1995, in conjunction with the ' newly formed International Continental Drilling Program (ICDP). ICDP's goals are to assist in development of major continental scientific drilling projects throughout the world, undertaken to understand, among several other themes, the manner in which Earth's climate

lL.Tittsca

I

L" Sebeäero

Lr/

Gr*n 8,xjo de Gualishc

has changed in the recent past and the reasons

for such changes. The recommendations from this workshop have been published by PAGES (PAGES Series 96- 4).

I

To help coordinate the fragmented conti. nental paleoclimate community and to {urther

I *

the ICDP-PAGES collaboration, one of the outcomes of the PAGES Continental Drilling Workshop was establishment of a lake drilling task force to develop a prospectus for lake drilling projects linked to the science agenda

Following solicitation of lake drilling planning proposals from the intemational science community, the task force evaluated and prioritized the proposed projects and submitted a prospectus for a S-year global lake drilling initiative to the ICDP Steering Committee in April 7996, fot

PEP

Site Srrvey Complctedlin ?ragrex Site Survey Propcscd

I: Iake drilling network

of the PAGES-PEP transects.

PEP

their consideration. At the same time, some

ing projects. Because ICDP funds are limited,

projects that were ready to proceed submitted individual pre-proposals to ICDP.

among other reasons, the PAGESlake drilling plan is meant to be used by the research com-

Aworkshop sponsored by ICDP took place in December, 1996, to facilttate ICDP's consider-

munity to approach all potential funding sources for lake drilling projects, nationally

ation of the proposed PAGES-PEP lake drill-

and

I

I RESEARCH AND WORKSHOP ACTIVITIES

With the support 0f the recently established Inter American Institute.for G.lobal Change Res,earch (IAI) seaeral working yrlups haae formed.to -coordinste interdisciilinary research that addresses thA Americas' interhemispheric paleoclimnte

o lce-core Study on the Environment qnd Climote of the Antorctic Peninsulo ond the Southern Pod of South Americq (loborotorio de Estroligrofio Glocior y

agenda.

lAl Funded PEP I Relqbd Proiects .

Vegelolion Hisr,ory from Fossil Rodent Middens in rhe Mid'lotitude Americon Deserts (J.[. Beloncourt, V. Morkgrof, [.

Groumlich) Fossil rodent middens from the deserts in South America (Argentina, Bolivia, Chile, Peru) will be collected and analyzed for

comparison with packrat middens from 2

internationally.

North American deserts OSA and Mexico) to resolve questions on human impacts on semi-arid rangelands; on how climatic extremes and variability affect long-term vegetation dynamics, biogeography and biodiversity in deserts; and on the interhemispheric interrelation between climate

change.

I

Geoquimico del Aguo y de lo Nieve (Argenrino); loborotörio de Pes -quisos Ant6rticqs e Glociologicos (Brozil); Depädment of Geogrophy, University of Colgory (Conodo); Lqborotoire Glocio' logie el Göophysique (Fronce) Ice core samples from the Antarctic Peninsula and the Patagonian Icefield will be recovered

and analyzed at annual to decadal resolution to identify atmospheric and climatic variabilt ity for the last 1000 years.

PEP lAl Funded Workshops r

Polenfiol Use of Biologicol Pro:ry Doto qs Climotic €honge Impoct lndicotors in South Americon Ecosyslems (C. Villogrön (Chile), M. Poez, A. Prielo, R. Villqlbo (Argentino), M.[. lorscheitter (Brozil) During a workshop held in Puerto Alegre, Brazil, in July 1996, members from the paleoclimate community developed a research agenda to evaluate the environmental impacts of future climate change on subtropical ecosystems inArgentina, Brazil and Chile.

The proposed approach focuses on analysis of multiproxy paleoclimate records for specific time slices in the past, considered potential analogs for future change. paleoenvironmental response, primarily be developed along

To enhance the

records

will

transects in ecotonal regions; 1) from the Pampas to the Espinal thornscrub, and to the Monte desert; 2) from the Patagonian steppe to the Monte desert, across the Andes, and into the Central

Chilean lowlands.

Highest priority in terms of facilitating future collaborative research was considered to be the development of educational and communication aspects. These include development of short courses on different topics in Latin American paleoclimates, such as on climate variability, past, present, and future; the development of paleoenvironmental and paleoclimate bibliographic databases, and of other databases related to the proposed research.

(Excerpt from workshop report

Villagrän)

by

C.

I

r lhe fusessmenl of present, Posl ond Future Climote Voriobility fiom Treeline Envircnments in the Americos (B. luckmon, Conodo) The western cordillera of the Americas comprise the most complete terrestrial latitudinal transect on earth and flank its largest ocean.

These mountains contain several ecotonal environments that have a proven potential to yield high quality multidisciplinary historical and paleo-climate data that can be used to address questions of climate variability at a large range of spatial and temporal scales. To focus on the potential of these ecotones within the context of the PAGES PEP-I transect a workshop entitled "TheAssessment of Past Present and Future Climate Variability in the Americas from keeline Environments" was held at Jasper in the Canadian Rocky Mountains, October 6th to 10th, 1996. The workshop

brought together climatologists, ecologists, paleoecologists, dendroclimatologists, and glacial geologists working in heeline environments inArgentina, Chile, Bolivia, Peru, CentralAmerica,Mexico, the US and Canada. The

goal of the meeting was to develop an interdisciplinary research agenda to address the response of treeline environments to recent and future natural and human related changes and the implications of these changes for natural resources in mountain environments. The pro-

posed strategy is to establish an interhemispheric network of climate and climate proxy data, from Alaska to Tierra del Fuego, at a nested range of spatial and temporal scales.

Such a data set would allow examination of the local and regional patterns of interannual and longer term climate variability and ultimately shed light on the causes of change.

Concurrent studies of contemporary environmental responses (e.9. at treeline, snow-line and by glaciers) will be used to benchmark the response of these systems to change. Co-funding for the workshop was received from NSFPEP I, the Canadian government agencies of

Atmospheric Environment Service, Environment Canada, Geological Survey of Canada, University of Western Ontario, Jasper National Park, and the Laboratory of Tree Ring Research,

I

Universily of Arüona.

o Fire ond GlobolChonge in Temperolre Ecosystems of Western North qnd Soulh

Americo (L Veblen, US) A workshop funded by a Phase I grant from the Inter-American Institute and held in Oregon in September 1996 under the auspices of AMIGO (America's Interhemispheric GeoBiosphere Organization) brought together scientists from Canada, the US, Argentina and Chile, to discuss a research agenda that would address the role of fire in ecosystem response to global change. The proposed approach focuses on the studey of present and past fire regimes, using dendrochronological and sedi-

ment charcoal analysis, across a range of biomes at different spatial and temporal scales in temperate ecosystems of westem North and South America. An interhemispheric comparison of fire regimes under different present and past land- use practices, different biotic and

abiotic conditions and disturbance regimes, different modes of climate and climate variability, etc., may help disentangle the influences of climate and human activities, a prob-

lem of great concern for future

land

I

oceanic and coastal zones of the eastern Pacifig

with their distinctive Upwelling and Eastern Boundary Current Ecosystems. The workshop provided the opporhurity to create anumbrella strategy to guide development of an overall Science Implementation Plan which included specific Research and Training projects focused

on the coastal and oceanic ecosystems extend-

ing from the intertidal zone to the pelagic region (0-200 km offshore). The science agenda and initial implementation plans developed focused on the following topics:

1) Large-Scale Climate (the framework of interannual, interdecadal and centennial climate change), 2) Atmospheric Forcing and Ocean Circulation in the Eastern Boundary Currents, 3)

Nutrient and Plankton Dynamics,

4) Near-Shore Ecosystems,

5) Long-term Ecosystem and Climate Histo-

/ Paleo-oceanography I Paleo-climatology), 6) The Human Dimensions: Socio-Economic I Issues and Consequences. ries (Paleo-ecology

.

Workshop on High Resolution Climolre Records from High Elevotion lce Corcs in the Americos (R. Brodley, D. Hordy, USA) To explore the opportunities for research on climate variability in the Americas from high elevation ice cores, a group of 20 scientists representing 11 countries met in San Carlos de Bariloche, Argentina from 11-13 December, 1996. The Workshop focused on the objectives outlined in the PAGES PANASH document (PAGES Report 95-1) for studies along the PEP-I transect.

Discussions focused on regions of the Americas from which additional ice core records could be recovered, and the value of each location in terms of understanding climatic variability. The geographical scope of the workshop discussion extended from the Antarctic Peninsula (-75"S) fo northem Ellesmere Island

(83'N). The meeting was financially supported by the Inter-American Instihrte for Global Change Research (IAI). The primary goals

of the workshop were to identify both the principal scientific questions which can be

-16

answered, and societal issues which can be addressed, by ice core studies along a NorthSouth transect through theAmericas, to determine which ice caps have the potential of yielding high resolution paleoenvironmental records, and to initiate discussions on programs of collaborative research.

November 1996, andbrought together 52 scientific experts from Chile, Peru, Mexico, the United States and Canada. The purpose was to design a research program which would implement the goals of IAI's Research Theme "Com-

The first session of the workshop was devoted to presentations reviewing the current state of knowledge in three areas: 1) Circulation regimes of South America and

I

management.

. Compqrolive Studies on Oceonic ond Coqslol Prccesses in lemperote Zones of the Eoslern Pocific (T. Boumgortner, USA) The workshop was held in Vina del Mar,

11

parative Shrdies ofOceanic, Coastal and Estuarine Processes in Temperate Zones" for the

meteorological observations at high elevations; (continued on page 4 bottom) 3

PEP II This report on PEP II actiaities uses selected abstracts and presentations from the 1995 Nagoya Symposium to illustrate the strength nnd diaersity of the resenrch being carried out within the unst and complex region spannedby the Transect.

Afull account of the Meeting and the Abstracts of all the Plpers can,be found in: Niiknmi,T, Matsumoto, E., Ohta, S. nnd SwedaT.'Paleoclimate and Enaironmental Variability in Austral-Asian Transect during the past 2000 years' . Proceedings of the 1995 Nagoya IGBP-PAGESIPEP-il Symposium,Nagoya. (277pp.)'

I I -

Th"

N"*

Zeolond Government

ho, ogr.""d to fund NZ$300k for drilling of Loke Poukowo on North lslond. This is one of the key sites identified os o port of the ICDP.

to"n Oooro"

d

NEW ZEATAND Tree-ring records from subqnbrctic forests in New Zeqlqnd \;

\{

iris

1, i''

\ti,

,

x9$lX Xr ut..

ISLÄNä r*u*!b\i''r

', *1

NEIV

! u ./-\ ZEALAN} ;l$ '-' i sR t \..._ '-'.

SOUT}I

ISLAND

' {"t u

.

J'-f : i ro.u

chronologies

STEWART

ISLAND

''-51) 'urr"o*" .''

,j

7979.

**u

Although there are shorter intervals of comparable warmth, the highest 2O-year periods of growth during the past 300 or more years of record for Stewart Island occurred during the middle 7950s-7970s, coinciding with record warming since around 1950 in New Zealand.

The updatedAhaura and Mangawhero series also show above-average growth during the recent warm period, with the highest 2O-year growth intervals since 1350 occurring in recent

s

,dt' 31,'f :

Fig.1 - Left: Map ot'New Zealand's North and South Islands and Stewart Island. Manapouri is location pinkpine site. Ahaura and Mangawhero Riaer Bridge are silaer pine sites.

Right: Map ot' Stewart Island and oicinity shorning location of pink pine tree-ring sites. DB, Doughboy Bau; RK, Mt, Rakeahua; PG, Pegasusan. Most recent collection (1995) was from Hellfire (HF) site, Ruggedy Mountains, northwestern Stewart Island. (in D'Arrigo, Buckley, Cook, Wagner, "Temperaturesensitizte tree-ring width chronologies of pink pine from Stewatt Island, New Zealand" , in press) of another

PEP I)

Methodologicäl techniques and issues of ice

core analysis;

3) Regionally-specific research accomplishments related to glacier-climate interactions and ice core drilling in the Americas.

Discussions were then conducted on individual regions of theAmericas where there are excellent prospects for recovering paleo-environmental records from ice cores. Specific needs and ideas for research projects in each regionwere identified and planswere laid out for integration of the various projects into a proposal to be submitted to IAI in7997. I

.

lorge-Scole Biosphere'Atmosphere Experiment in Amozoniq (tBA) (C. Nobre et ol., Brozil) To foster understanding of regional-scale transport in Amazonia, of energy, heat, mois-

of silver pine (Lagnrostrobus

,,v

i:--**i ll l$ lüü

4

southern New

originally published by LaMarche et al. in

ü

paRe 3 -

for

coLnsoi), closely related to the huon pine (L. franklinü) of Täsmania, for two sites: Ahaura, South Island, and Mangawhero, North Island, New Zealand. Both are updated from series

t$l'Äat)

(conlinued from

I nologies for the Southem Hemisphere include several we have recently produced for pink pine (Hal ocarpus bit'ormis) from Stewart Island, the southernmost of the three main islands of New Zealand (D'Arrigo et al. a and b. in press). These chronologies are positively correlated with wafin-season land and marine temperature records

Mtf[tilNsw

2)

femperature-sensitive tree-ring width chro

Zealand and vicinity. We have also developed

':. :

,i1.

I

decades. (continued on next page)

ture, carbon and other trace constituents, and their interactions and feedbacks, process studies at local to meso-scale are proposed, coordinated under the LBA experiment. To disentangle the role of human impact from natural environmental and climate variability, these experiments include a paleoclimate component, that focuses on identification of the effects the different past precipitation and temperature modes on Amazonian ecosystems.

The proposed plan, jointly developed by B. Turq (ORSTOM, Brazil) and P. Colinvaux (Smithsonian, US), calls for development of a network of multiproxy paleoclimate records analyzed with decadal to millenial time resolution. The network of paleoenvironmental records overlaps the network of sites proposed {or hydrological, biochemical and ecological process

studies.

I

.

Dendrochronologicol Studies in lropicol Soulh Americo whh Speciol Emphosis on Bolivion Forests (J. Boninsegno, R. Villqlbq, F.A. Roig (Argentino), J. Argollo, S. Beck (Bolivio)) Field reconnaissance, collection and dendrochronologic analysis of different tree taxa from the subtropical and hopical forests in SouthAmerica should provide information on the potential of tree-ring research for paleoclimate in these poorly known environments.

Sugmrrro

rv Dr. Vru Mmxour

lnstitute of Arctic ond Alpine Reseorch University of Colorodo Boulder, Colorodo 80309-0450, USA Phone: 303 492 5117

Fox: 303 492 6388 e-moil: morkgrof@spof.colorodo.edu

a.

PEP II Fig.2

Fig.3

graph: Hellfire, Ruggedy Mt, Stewart Island pink pine chronology.

Bottom graph: actual and estimated gridded warm-season temperature and

Top graph: update of silaer pine chronology t'or Mangawhero Riaer Bridge, North Island, merged with raw data t'rom chronology (LaMarche et aL,1979).

Bottom graph: actual and estimated Auckland TrJnrm-seasln temperatures based on Mangawhero chronology, Temperature and tree-ring data prewhitened to account for et't'ects ot' autoregression.

Top

tree-ring data prewhitened to account for

et't'ects ot' autoregression.

Hellfire, Stewort lslonds pink pine ring width chronology

Mongowhero ring-width chronology, LoMorche ond Tol merged doto

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1450

1550

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YEARS

1750

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Actuol-estimotedworm seoson Aucklond temperotures

Hellfi la' pink pine ond gridded wor m seoson

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These chronologies supplement previ-

Villalba 1993, Villalba et

a1.,1994).

Rosrlrr D. D'Annroo, Eouno R. Coox,

Bnrt.tomr

ously published tree-ring data from New

Together these tree-ring archives improve our

M. Bucxlrv rro Paul J. Krusrc

Zealand (LaMarche et aL.7979, Norton et al 1989), Tasmania (Cook et al. 7997,7992,1994),

geographical coverage and long-term perspective of climatic variability for data-sparse

and southern South America (Lara and

regions of the Southern Hemisphere.

Full references con be obtoined from lhe first outhor ot: Tree-Ring Loborotory Lomont-Doherty Eorth Observotory Polisodes, NYio964,

.

USA

I

CHINA Pqleoclimqte records qvqilqble frcm Chinese historicql documents Historical documents are a major resource

of paleoclimate information in China, They contain the records on drought, floods, rain, snow, freezing, frost, wind, dustfall, atmospheric physical phenomena such as twilight, sky-coloq, etc., and past records of crops, famine, and insects pests etc.. The earliest one dated from 780 BC.. A systematic study has been conducted on 8128 sources including government history books, local gazetteers,

and literature etc.. After detailed proof-reading, cross-checkilg and establishing the chronology of events, a Chinese historical climate database has been established in the NCC (National Climate Centeq, China).

A map locating all the sites of records can be obtained from the author.

The records havebeen employed in recon-

Table 1.

Oaerall percentages of the paleoclimate records mentioning dit't'erent items in Chinese historical documents

Item

Percent% 18

Item Percent

rain snow storm hail frost 22 9 3 2 5 1 cold hot locust epidemic famine harvest 27 6311,73

drought flood

%

dust 2

wind 5

other

The table shows some statistics for major items ot' the database.In addition, ther are the daily weather records extracted from some priaate diaries, and goaernment weather reports in historical times.

structing regional climatic series mapping the real conditions of extreme climate cases and compiling a chronological table of some rare paleoenvironmental events.

References:

,1995,

Zranc Dr'rr Notionol Climole Center Beiiing 100081, Chino

Poleoclimote ond Enviromentol records ovoiloble from Chinese historicol documents ln: Poleoclimote ond Environmentol Voriobility in Auskol-Asion Tronsect during the Post 2000 Yeors. {eds. T. Mikomi, E. Motsumoto, S. Ohto ond T. Swedo) Nogoyo University, lopon,P.20-26.

Zhong De'er,

T

PEP II CHINA Dust emission from Chinese desefi sounces linked to lorge'scqle vqriqtions in

otmospheric circulqtion I

3i)"

ll

1. Fukang @4" 17'N, B\T'E),2 Aksu (4122'N, 80 "43' E), 3. Qira (37 %' N, 5234' E), 4, Dunhuang (40 "16'

N, 94"10' E), 5. Golmud (36 %2' N,

9

6 %4'

E),

uguan (40 %8' N, 9 8 "31' E), 7 . Heiquan (4026'N , 100"16'E), 6.linyuguan (40"38'N , 9 8 "31' E, B. l artai (40 "34' N, 106 "34' E), 9, D alad Qi (40 "63' N, 110'6' E), 10. Yulin Ă&#x; I 37' N, 109 %6' E), 11 . Dingbian (37 37'N , 107 34' E) , 12 . Minqin (39 "17' N, 10 3 "10' E), 13. Lanzhou, 1 4' Xian, 16' 6, I iay

Luochuan, 16. Beijing, 17. Hefei.

Source Regions: I-Western deserts deserts (6 ,

7

, B);

(2

,

3

, 4) ;

Il-Northern high-dust

Ill-Northern low-dust deserts (9-12).

Depositional Regions: A: Chinese desert regions (1-12), excluding three sandy lands in northeastern China; B: Chinese Loess Plateau (13,14), C: Historical NE dustt'all region, 34.3-41'N , to the east of 114% (16);

D: Historical SE dustfall region, 27 '314.3"N, to the east ot' 104.7 % (17); E: North Pacilic Ocean

The major sources for Asian dust lie in deserts of northern and northwestern China, but little information is available on the quan-

tity of dust produced or the distribution of source regions. Dust pulses are evident in Chinese loess, but it has not been possible to apportion the contributions among source regrons or even pinpoint the source areas. Data irom five Asian/Pacific regions indicate that -800Tg of Chinese desert dust is injected into the atmosphere annually; about 30% of this is re-deposited onto the deserts, 20% is transported over regional-scales, and50% is transported to the North Pacificic and beyond.

Elemental tracers reveal high-frequency variability in Chinese loess related to dust inputs from western desert sources vs. northern highdust and low-dust desert sources. These shifts inAsian dust source regions are synchronous with large-scale variations in atmospheric circulation over the last glaciation' Full references ore ovoiloble from the outhors who

prepored the report.

The mnp shows the

winter monsoon regimes of

eastern Asia, aerosol samplinglocations ft-12) in Chinese deserts, the sites (open squares with numbers) t'or the data cited, source regions (Sources L il, m) and depositional regions (Regions A, B ' C,

CHINA Micrcbqnding of stologmite qnd its significqnce Stalagmites are a kind of speleothem able to provide climate information with an annual resolution and much longer time span comparing to tree rings. Two aspects of annual banding of stalagmite have been reported: the luminescent microbanding which is only observed under a fluoromicroscope

Shopov 1987,1994andA. Baker 1993) and the lamina which are visible to the naked eye (D. Genty 1996). Recently, the authors have studied a stalagmite from Beijing Shihua Cave within the East Asian monsoon zone and found under the polarizing microscope (Y.

the transparent micro-banding is very clear.

The preliminary results show that about 1100 continuously microbands are in the upper 45mm of the stalagmite (Fig.I).

Eachband, taken as annual deposition, mostly tens of microns in thickness, consists of two

Xno Y. Zrrtto, Zxl 5. Att Stote Key Loborotory of Loess ond Quolernory Geology Acodemio Sinico, P.O.Box 1Z Xi'on /10054, Chino

Rrcxlro Antmoro

parts:

Center for Atmospheric Chemistry Studies, Groduote School of OceonogroPhY

I a light part at its bottom which may be deposed from the "old water" in the fissures

Universitv of Rhode lslond

N"t.g"it*tt, 6

Rl 02882-1

197,

USA.

I

, E) for Asian dust. The preaailing northwester,Iy winds (arrows) associttted zaith the Siberian High (HPa) and westerly winds from central Asin entrain the bulk ot' the Chinese desert dust deliaered to the depositional areas.

D

displaced by annual rainfall,

Fig.1: The 1100 annual transparent microbands ot' the stalagmite t'rom Beiiing Shihua Cazte. The order the let't to the from-the top to the bottom and from right in the figure is in the direction from the top to the base in the stalagmite. The scale is I mm

illustrating the size ot' the banding. The round dots in the first row of photograph are pen-matks.

PEP II dark one on the top which may be deposited from "fresh water" which comes from the overlying soil and contains more organic -a

d

L_l_J*r*l*-:

matter.

The cave was developed in Ordovician

limestone. The stalagmite which is about 2O0mmhigh and columnarin shape, was taking in the drip water when it was cut. The AMS 14C dating suggests that the stalagmite has an age less than 2000 years.

It

seems rea-

sonable to suppose that the rythmic banding

is comparable to the fluctuations in the annual precipitation which has only one annual peak value in most years in the monsoon zone and undergoes interannual changes in a wide range similar to the bands. Assuming this interpretation correct, the authors have developed the time series of band thickness

1920

1774

| , L

.t!92

| , I , _.1_*-:_ l , | , 1,,

r^0

ttt0

rrrryrflrl;

rrnning eurvr ofthr indcx ofdrought and ffoorl

I e4a-4

21nl)

ä

3{ittld)

3ü

,4

ylo -l

I

l{ry} €

5{|E*}l*

c 20 --l EI

s

tl

tr

10 --l 7

o.# a M,a3?$rlS C-'l4l f

lointr running cnrus

il

llr0

thirhto.r 0f b*nding 1* *

l2Oy BP{MS C-14}

[_r

ry*r*1*r*1**r*1--;1

550 500 450 . 400 350 300 ?50 ?00 150 10!

50

Nunrhrr nflhr banding ( eountrd fronr tln tnp )

and compared them with the index of drought and flood drawn from historical documents of the last 500 years (from 1470 to 7992 yr AD, Fig. 2s) and the instrumental record of precipitation from 1951 to 1980 yr AD (according to the data from National Climate Center, Fig.2b). The coherence of these curves suggest once again that the banding has an annual resolution. Consequently, the light and dark parts for each band may reflect seasonal hydrological changes. With the curve

,6ä

Tlhin*cllmdhS(t*) ?m

Itrcipilrtion {nm}

,

''Teo 5il!

2m0

1060

0

of thickness change the authors reconstruct an

annual resolution climatic history of the last 1100 years in the Beijing area (Ftg. 2c). The precipitation was at its height in about 900 yr BP and after that time it was decreasing to the lowest in about 515 F BP (start from 1980 yr AD), then gradually increasing up to its 20th cenhrry maximum in the 1950's. 136-year,50year, 1.8-1.6-yea1, 11-year and 5.8-year climatic

Ik

thick

lht ir

ll

pnin*

t*nlng,lf mmmnct

end D nrtanl

rfiy

rycles are observed.

Full references ore ovoiloble from the outhors.

400

Tlr.r Mrr,rc, Lru Tuncsrrxc, Qrr Xrlocuaro, lnstitute of Geology, Chinese Acodemy of Sciences, Beijing l0029,Chino

6ü0

80ü

Nunrher ofthc l}atlds ( coilnl.tl fronr lhc lop )

Zslre Dr'rr Notionol Climole Center Beiling 100081, Chino

r

Fiq.2: 2i: Comparison between the aariation of banding thickness and the index of drought and flood recoaered from historical documents oaer the last 500 years.

2b: Comparing'the change of banding thickness with the instrumental records of precipitation from 1951 to '1980 yr AD. 2c: The aariation of the banding thickness in the last 1100 years, which may represent the change in precipitation.

I I -

A Chin"r" version of the PANASH-PEPII report hos been produced ond is ovoiloble from Guo Zhentong ot: lnstitute of Geology, Chinese Acodemy of Sciences, P.O. Box 9825, Beiiing I 00029, CHINA phone: +86 10/6202776 ext.345l330, fox +86 10/62052184or 64919140, emoil: ztguo@mimi.cnc.oc.cn

A

French version of the PANASH-PEP

Further detoils

lll report is in preporotion.

will be given in our next

PAGES Newsletter.

PEP II TAIt^/AN Corql SrlCq os o High Precision High Time-Resolution Pqleo-Thermometer for Seq Surfqce Temperqlure: l,ooking for ENSO Effucts in Kurcshio neqr Tqiwqn

Applying the newly developed coral Srl Ca paleo-thermometry to core samples from

Our coral samples znere

southern Täiwan, we have detected a 1.-2C warming in the sea surface temperature (SST) for the winter of 7982-83. Our tentative interpretation is that the strong ENSO of 1,982-83 caused the warming through an enhanced Kuroshio Current or a reduced northeast winter monsooon. Howeveq, detailed comparison between the proxy SST record from coral and the SST in the Comprehensive Ocean-Atmosphere Data Set (COADS) revealed several discrepancies of similar size implying that further study is required to establish such a possible teleconnection.

Tvproor Lr:I, Ctumr-Clou Sxrr,rr, Cxuto-Ho

drill

cores

from large Porites heads in Kenting I

Lutao

and Lutao. These corals haae been

r

growing continu-

äö)?

;Yl ,ll-/r)

ously from about 200 years ago. knting is where rae calibrated the SrlCa

4! aJ

I\TN \rri s/{

as. Sea Surface Temperature (SST)

1

i E(\ , i-$J€t

relationship, It

t'aces

the Bashi strait which is the only deE opening ot' the South China Sea to the Pacit'ic. Lutao is

Wlnel

Crrr.r-Hsrx Cxru2, Crmro-Frxc Dlt2, Ju-Cxrr.r Cx:H2

l: lnstitute of Eorth Sciences 2: lnstitute of Oceonogrophy,

in the Kuroshio Current and our sampling site there (marked W star) is directly exposed to

Notionol Toiwon University Full references con be obtoined from Typhoon Lee ot: lnstitute of Eorth Sciences Acodemio Sinico

PO.Box l-55, Nonkong Toipei, TAIWAN R.O.C. e-moil: typhoon@bioo3.bioo.sinico.edu.iw

ll5

the winter monsoon from the north east.

a

I

Lutao ?orites lobata 29

g 4)

L

c)

23

{)

F

(-)

a

23

2l

r2.t I 16 l l l 106 lül

96 91 86 8l

76 71 66 6l

<1

46

41

31 26

2t

The 1981-90 SST int'erred't'rom SrlCa of Lutno coral assuming Lutao seawater has the same SrlCa as the calibration site, The wint:er SST was u)armer than usual by 1-2T for 1982-83 and 1987-88, both of which coincide with ENSO eaents. Note that the absolute SST scale Lutao is still uncertain

knting,

for

because the measurement of Lutao seawater SrlCa is still in progress and we haae assumed there that it is the same as Kenting (probably not quite conect). Howeaer, a change in seawater SrlCa does not affect the

relatiae difference between SST ot' one winter to that of other winters t'or the same site. We suspect that this warming was the result ot' the decrease in cooling caused by a particularly weakNE monsoon since the analysis of COADS wind data reoealed an unusually weakNE monsoon for the winter of 1982-83 (Chao et aL 1996, Prog, Oceanography, submitted).

WORKSHOP REPORTS I

Recommended Action 2: o comprchensive study of climqlic

st PAGES/CIIVAR Working Grcup Meeting

IGBP-PAGES and WCRP-CLIUAR recently teamed up to establish the PAGESICUVARWoTking Group (WG). The impetus for this new WG stems directly from theNoaember 1994 joint IGBP-WCRP worlshop (Venice,Italy) on climate aariability and predictability, and from the recognition that the new WCRP CLMARprlgram needs a firm paleoenaironmental perspectiae to meet its needs.

With the establishment of the PAGESICLMAR WG, PAGES (Past Global Changes) becomes one of the first IGBP (International Geosphere-Biosphere Programme) core project to also serae the WCRP (World Climate Research Programme).

fhe

first meeting of the PAGES/CLIVAR was just held (October 24-2il in

I WG

Villefranche-sur-mer, France, and included participants from both the PAGES and CLIVAR research communities.

Building on the recently published 'PAGESCLIVAR Intersection' document (edited by J. C. Duplessy and J. Overpeck, and available from either PAGES, CLIVAR or the Internet

WWWeb at http: / / www.ngdc.noaa.govl paleo/reports/clivar.htm), the WG agenda called for a critical review of what paleoclimatic data and methods are available for addressing CLIVAR seasonal- to centennial-scale climate variability issues. This led to discussions focused on specfic areas of potential CLIVAR-PAGES interaction, and then to ways to improve the interdisciplinary interaction between the PAGES and CLIVAR communities.

recommendations wiltr be published as a joint CLIVAR/PAGES document. The recommendations are summarized here.

As a general preamble, it was decided that PAGES/CLIVAR interactions focus on: - societially-relevant climate variability (e.g., droughts, floods, storms) and the processes driving this variability, with the recognition that extremes of the 20th century were small relative to those of the preceding centuries and

A comprehensive shrdy of climate variability given climatic states and forcing that are significantly different from today. The pri-

mation on how these phenomena are affected

mary objective acknowledges the fact that global climatic forcing is changing dramatically, and that this means that future climatic variability couldbe distinctly differentfrom any of the last 150 years. The paleoclimatic record suggests that each of the above-mentioned key phenomena may have been significantly different during the mid-Holocene and Last GlacialMaximum. Thus, specific attention should be given to reconstructing, understanding and modeling climate variability of 6,000 and

by changes in climatic forcing. Among these

21,000 years before

behavior that can be investigated only with the aid of a paleoclimatic perspective, and only the paleo-record contains empirical infor-

phenomena are specifically: - ENSO atmosphere-ocean interactions and exhatropical linkages; - Tropical/North Atlantic variability, and interactions between hopical processes and regional drought, the North Atlantic Oscillatiory and thermohaline circulation; - Asian/African monsoon dynamics, linkages with ENSO and exhahopical variability; - shallow meridional ocean circulation and other processes as a mechanisms that link tropical and extratropical climate variability.

It was concluded that many paleoenvironmental tools are available for improving our understanding of these phenomena, with

A ftrll report on the WG presentations and

voriobility

particular interest in insights that can be obtained from coral, ice core, sediments, historical and tree-ring data. These proxies, in con-

junction

with modeling studies and

present.

.

Recommended Acfion 3: o detoiled invesligotion of tronsient climqtic evenls

A detailed investigation of major abrupt transient climatic events of the Holocene and Pleistocene. The focus here is on climatic events of the past that, if they were to occur today, would have profound impact on human societies. Past abrupt changes occurred on seasonal to decadal time scales, and provide key insights into how the coupled climate system may respond to altered climate forcing in the future. This recommended PAGES/ CLIVAR action is aimed at avoiding devastating climatic "surprises" in the future, and should be aimed ultimately at developing a predictive ability to simulate major abrupt changes in climatic variability.

interdisciplinary interaction between the CLIVAR and PAGES communities, will provide a powerful basis for attacking several specific CLIVAR-relevant objectives. It is recommended that the above-mentioned phenomena and mechanisms be examined with a view to the following specific actions:

The WG discussed linkages to other projects. Most relevant were the PAGES/ CLIVAR ARTS (Annual Records of Tropical Systems) Initiative, and the Paleoclimate Modeling Intercomparison Project (PMIP), both of which focus on meeting the specific PAGES/ CLIVAR priorities listed above. Anumber of

millennia; - understanding seasonal to century-scale variability as a prerequisite to reliable predictive capability, with the acknowledgment

o detqiled study of climotic voriqbility

from the paleoclimatic record that decadal to century-scale variability modulates seasonal

A detailed study of the climatic variability of the last 400 years (globally) and the last 1000

to interannual variability, and that climate

years (where possible). The Boal here is to provide the fust comprehensive understanding of

The WG meeting ended with a discussion of how interaction between the PAGES and

cades or longer;

natural (non-anthropogenically-forced) sea-

unraveling key phenomena and mechanisms of climate variability; - understanding tropical-exhahopical interactions.

sonal to interdecadal variability, and to put the

CLIVAR communities could be improved. It is recommended that both focused interdisciplinary science meetings and cross-disciplinary

states can

abruptly change and persist for de-

-

The intersection

of CLIVAR foci

PAGES capabilities led to the

and

identification of

several key phenomena and mechanisms for joint study. Each of these phenomena exhibits

Recommended Acfion

l:

last 100 years in the context of the last 1000. \,Vhere possible, the emphasis

willbe

on

deriv-

ing and using global fields of multiple climatic parameters (e.g., temperature, precipitation, sed-ice), and on the combined use of reconstructed time series of both climate observations and climatic forcing (e.g., SS! volcanic optical depth, solar, trace-gas, and aerosols).

additional PAGES activities and tasks are also of great relevance to PAGES/CLIVAR. Increased coordination with these efforts will be a goal ofPAGES/CLIVAR.

short-courses be held at regular intervals in the future. In many cases, the science meetings should be collaborative with existing PAGES

and CLIVAR efforts. Improved interdisciplinary data sharing should also be built upon the existing PAGES data management program at the World Data Center-Afor Paleodimatology, 9

with a special PAGES/CLIVAR Internet (\IWVVV) interface

for data and information

sharing. Last$ the PAGES/CLIVARWG calls for greater participation of paleoclimatologists in other CLIVAR activities (i.e., those associated with GOALT Deden and ACC).

This summary was provided by PAGES/ CLIVAR WG Co-chairs J-C. Duplessy and |.

Overpeck. Additional information, including a listof WG members, canbe obtainedbycon-

tacting either PAGES or CLIVAR. Afull report of the WG meeting will soon be published (in hard and electronic forms) jointly by PAGES and CLIVAR.

The PAGES Scientific Steering Committee welcomed three new members at the start of

80303, USA

Phone: 303-497-6172 Fox: 303-497-65 I 3 e-moil:

ito@ngdc.nooo.gov

1997.

I

AND MORE...

I

PEP lll Workshop Bierville (France), September 12-75, 7996 FmHgorsr Gmsr Loborotoire d'hydrologie et g6ochimie

isotopique

-91405 ORSAY

:33 (l) 69 15 67 56, Fox:33 (l)69

Tel

15

URA CNRS 223

FRANCE

49 17, e-moil: gosse@geol.u-psud.fr

(Annual Records of Tropical Systems) Workshop PAGES/CLIVAR Kauai (Hawaii), September 27 -30, 1996

lARIS

Jur.n Cou Geologicol Sciences/INSTAAR Compus Box 450, University of Colorodo- Boulder CO 80309-0450 Phone: 303"492-0595, Fox: 303-492-6388, e-moil: coleie@spot.colorodo.edu

I

Continental Signals of Paleomonsoon D)mamics in Africa: Inter-Hemispheric Perspectives INQUA-PAGES Paleomonsoons Project and Cooperative Research Project 389 Siwa Oasis (Egypt), 11-22lanuary 7997 Srrrlt.t Kro:pnrH Coordinotor, INQUA-PAGES, Poleomonsoon Project Off ice Free University of Berlin, Podbielskiollee 62-D-l4195 Berlin, Germony Phone: +49 {0) 30 838-6368, Fox {ISDN): +49 (0) 30 841-00363, emoil: skroe@zedot.fu-berlin.de

I

Arrivols...

Dr Patrick De Deckker, who was born in Bel-

The following workshops hove token ploce on the lost few months with PAGES sponsorship ond/or porticipotion. For further informotion, pleose contoct the orgonisers noted below.

Bdt. 504, Universit6 PARIS Xl

New members qt the PAGES Scientific Steering Committee

Dn. Joxrrrrur L Ovrnprcx NOAA Pcleoclimotology Progrom Notionol Geophysicol Doto Center 325 Broodwoy E/GC Boulder, CO

INSIDE PAGES

gium, is Reader in the Department of Geology, The Australian National University. He has published widely in taxonomy, ecology, paleoecology, water chemistry, geochemistry, paleolimnology, paleoceanography, paleoclimates, limnology and archaeology.

Dr G.B. Pant is Deputy Director of the Indian Institute of Tropical Meteorology and Head of the Climatology and Hydrometeorology Division. His main academic interests lie within the fields of Atmospheric energetics, Climate and climate change, Paleoclimatology and Climate Modeling.

DrDominique Raynaud is Research Director of the CNRS 'Laboratoire de Glaciologie et Gdophysique de l'Environment' in the University of Grenoble. He has participated in several, mainly Antarctic, Polar expeditions and published widely on ice core research, the carbon cycle and paleoclimate. He also serves

PAGES as the leader of the Antarctic PICE programme.

... ond deporlures

Modes and Mechanisms of Holocene Climate Variability Workshop

The pleasure of welcoming new members

Holocepe miniconference

to the PAGES SSC is always mixed

Lamont (USA), 73-74January 1997 Prrrn B. orMrrocn

for departing members.

At the end of 1996, Claude Lorius, Eric Odada and Bob Wasson ended their period of service. All made outstanding contributions to the work of PAGES, Claude especially in the area of Antarctic Ice Core-based research for

Lomonl-Doherty Eorth Observotory Polisodes, NY 10964, USA Phone: (914) 365 84B3, Fox: (914) 365-2312, emoil: peter@ldeo.columbio.edu

l-tn" *..lle

Medql for Hqns oeschger

which he has been honoured intemationally at the highest level, Eric for his major contribution to PAGES Science in A{rica not only

Hans Oeschger will be receiving this year the Revelle Medal from AGU during the upcoming Spring AGU session (March 1997), organised in his honour by Ed Brook and Todd Sowers and entitled "Biogeochemistry of trapped gases in ice cores".

President of the Ocean Sciences Section from 1956 to 1959, Roger Revelle made substantial contributions to the awarness of global change. Established in7991., the Revelle Medal recognizes oustanding accomplishments or contributions towards the understanding of the Earth's atmospheric processes including its dynamics, chemistry, and radiation; and towards the role of the atmosphere, atmosphere-ocean coupling, or atmosphere-land coupling in determining the climate, biogeochemical cycles, or other key elements of the climate system.

Edward N. Lorenz *as the first recipient of this medal, given not more often than annually. The previous recipients were Edward N. Lorenz (1992), Syukuro Manabe 0999, F. Sherwood Rowland (7994),Wallace S. Broceker (1995), Robert E. Dickinson ,l%I

t0

with regret

through his work with IDEAL, but

also

through his wide knowledge and contacts, Bob for his commitment both to southern hemisphere matters and to the theme of human impact within the overall framework of

GlobalChange.

I

Cindy Jones, who, along with Ulrich

I

Schotterer, takes the credit for the extremely attractive and professional format of our 1995 publications, is now a member of the PAGES staff. Her first task, as Publications Officer has been to produce this Newsletter.

I

NATIONAT ACTIVITIES CANADA Wqtâ&#x201A;Źr qnd Climqb Studies in Cqnodq using lsotope

GERMANY

Trqcers: Post, Presenl, Future

Prciect'ACACIA' (Arid Climqb, Adoptotion qnd Culturql Innovqtion in Africo) 1995.2010

Cooperotive Reseqrch

3 1 st Jonuory ond I st Februory I 997, Woterloo, Conodo Report of the workshop

This two-day workshop was convened with the twin aims of reviewing the state of water and climate research in Canada using isotope tracers and investigating the establish-

ment of a revitalized "Canadian Network for Isotopes in Precipitation", as a contribution to the international GNIP program (Global Network for Isotopes in Precipitation), which is

the well-known offspring of long-standing IAEA/Ii\MO efforts to document the distribution of water isotopes in the global water ryde.

About 60 participants from university, government, and the private sector gathered for two days of presentations and discussions at the University of Waterloo, Ontario, Canada.

The workshop was sponsored by Environment Canada, through the Atmospheric Environment Service (Downsview Ontario) and

the National Hydrology Research Institute (Saskatoon, Saskatchewan), with additional

panded network of 20-30 meteorological stations collecting monthly-composite precipitation samples for isotopic analysis was desirable and feasible, building on the network of sites in Canada currently contributing data to GNIP. The existing "CNIP" includes Ottawa (1953-present) and eight northern stations (1989-present), plus data in the GNIP archive from previous monthly-composite sampling campaigns at a number of other sites in the 1970s and 1980s. Various targeted research projects, including ongoing event-based pre-

cipitation sampling

in

Winnipeg

(1992-

present), have also generated abundant data that are not yet formally archived. A revitalized CNIP would constitute avaluable Cana-

dian conhibution to international water and climate studies, as well as providing a framework for nested campaigns requiring more

support from the Canadian Geophysical

intensive temporal or spatial sampling, such as the Mackenzie Basin Study of the Global

Union, the Waterloo Centre for Groundwater Research, and several other Waterloo-based university research bodies.

Background on international GNIP activities, the PAGES perspective, and comments on

Energy and Water Cycle Experiment (GEWEX-MAGS).

The workshop culminated in a provisional agreement to work towards the establishment of a rejuvenated and expanded CNIP, based

experience gained from national isotope networks in Switzerland and Germany were pro-

on a model in which responsibilities for

vided

in

Plenary Lectures from. Klaus

Froehlich (IAEA) and Ulrich Schotterer (PAGES). Special guests

EmiIto (Universig of

Minnesota) and Carol Kendall (US Geological Survey) offered narrative on the current situation in USAregarding potential for developing a national precipitation network and the existing USGS isotopic data base from surface waters. Subsequent presentations were seIected to sample the broad spectrum of past and present activities in Canada, falling into three general areas: assessment of existing isotopic data from past and ongoing precipitation sampling in Canada and efforts to define the

sample collection and analysis would lie, respectively, with the Atmospheric Environment Service of Environment Canada and a consortium of university and government isotope laboratories. A special sub-committee of the Committee on Isotope Tracer Techniques within the Hydrology Section of the Canadian Geophysical Union will assume responsibility for overall scientific direction and adminishation, and the continuity of the program.

Aspects of the challenges and opportunities associated with CNIP will also be addressed at the upcoming annual meeting of the Canadian Geophysical Union (Banff, 4-9

May 1997) and the ISOBALANCE Interna-

nature of isotope-climate linkages; atmo-

tional Workshop on Application of Stable Iso-

spheric studies, including discussion of carbon and oxygen stable-isotope signals in atmospheric carbon dioxide and links with the water cycle; and the use of isotope tracers in hydrologic, paleohydrologic, and ecologic shrdies of surface and ground waters, groundice, and the water isotope records preserved in other archives.

The presentations demonstrated clearly that substantial Canadian expertise exists in this field, complemented by the capacity and willingness to train young researchers. The discussions also led to consensus that an ex-

topes in Water Balance Studies (Saskatoon, 14-

l9Jdy

1ee7).

Further informotion obout the CNIP Workshop ond ongoing octivities con be obtoined through: Troruas W.D. Eounos Associote Professor Dept of Eorth Sciences University of Woterloo 200, University Avenue Wesl Woterloo, ON N2L 3Gl, CANADA Phone:

+l 519 888

Fox: +l 519 e-moil:

4567 ext3236

7460183

twdedwor@uwoferloo.co I

This long term research initintiae in .

Germany clntfĂźns seaeral sub-proi ects of interest to PAGES. Three of these are ed br iefly b el ow.

Further information can be lbtained from the prlject leaders through Stefan des cr ib

Kroepelin.

CTIMAIIC CHANGE AND HUMAN SEITLEMENT BEMEEN IHE NITE VAttEY AND THE CENIRAT SAHARA

In follow-up to the long-term interdisciplinary project, "8.O.S." (Settlement History of the Eastern Sahara; 1980-1995) further and more detailed research will be conducted in the Northern Libyan Desert. This sub-project focuses on the initial stages and spread of food-producing economies, the

general question regarding the mono- or polycentric development of Neolithic phenomena, and the relevance of these processes to the birth and rise of Egyptian civilization.

Since the ecological setting for human

activity in this region can be divided into three larger environmental zones - the summer rains in the North, winter rains in the South, and the Nile Valley in the East - the study of regional climatic development is a necessary prerequisite for understanding the historical development and the possible role and range of interregional contacts' Therefore, a detailed regional chronology must be determined based on geomorphological / sedimentological analyses as well as archaeological excavations, which take into consideration palaeobotanical and archaeo-zoological aspects.

Within the general framework of the Cooperative Research Project - man and his environment - this sub-project focuses on the earliest indications of the interdependence between socioeconomic development and environmental conditions, investigates the

transition to a productive economy, and therefore endeavours to record the initial stages of cultural change, which apparently began in the north of the continent and folIowing a few millennia would later affect the south.

t1

NATIONAL ACTIVITES WADI HOWAR . sEITEMENT AREA AND IHOROUGHFARE AT IHE SOUTHERN MARGINS OF THE TIBYAN DESERT

Located on the southern fringes of the Libyan Desert, the Wadi Howar is the largest dry river system in the Eastern Sahara stretching over 800 km from eastern Chad to

the Nile. Geomorphological and palaeontological investigations have confirmed that this wadi was still an important tributary of the Nile during the early Holocene; later it was transformed into a chain of freshwater lakes fed by local rainfall. Since the Wadi Howar was both a settlement area with eco-

Iogically favourable conditions and a route connecting the inner regions of Africa and the Nile valley, the several prehistoric sites which have been discovered confirm that it was an important site of population activity and interregional cultural contacts.

The rich archaeological and archaeozoological potential and the geomorphological and topographical variety of these sites provide detailed insight into the structures of the settlements and their strategies for survival. They also supply the necessary data for a reliable chronological and clima-

tological sequence. The processes of climatic and economic change - due to desert encroachment - and their cultural implications will be examined with regards to the development and function of regional adaptation strategies as well as the large-scale role of the Wadi Howar as a connection between the Sahara and regions further south.

AND THE TAIE HOTOCENE SENEMENT OF NORTHERN PATAEOECOTOGY

NAMIBIA

In the first phase of the project, longterm survey activities (including test excavations) will be carried out in close cooperation with botanists and geographers. Only then - and after the archaeological potential and the state of preservation of organic matter (especially botanical remains) has been examined - can more detailed archaeo-

Although the state of archaeological research in northernmost Namibia is not as advanced as in other parts of the country, the area has played an important role in many discussions regarding later prehistoric settlement of the whole of southern

Africa. This particularly applies to

determine how adaptation strategies and innovations varied when subject to different and changing environmental conditions.

logical studies be designed. Although the focus of the project is environmental and economical aspects and the different modes of human adaptation, it also aims at contributing to a more reliable chronological framework for the last 3,000 years of human and environmental history in this region.

the

routes o{ the so-called "Bantu migrations" and the spread of food production and iron technology. This region, that extends from the Atlantic to the Zambesi, also provides various ecological settings for study: from desert to savannah and woodland conditions. Thus a primary aim of the project is to establish several relatively smaller study sites along a west-east transect, in order to

Bosed on o text submitted by:

Srrrax Kno:pnrl Coordinotor, INOUA PAGES Poleomonsoons Proiect Poleomonsoon Proiect Off ice Free University of Berlin

Podbielskiollee 62

D-14195 Berlin - Germonv Phone: +49(0)30 838-63e8 Fox {ISDN): +49(0)30 841-00363 e-moil:

skroe@zedot.fu-berlin.de

I

PEP II PAGES

Prcgrom in Toiwqn (1992-1996l.

The Past Global Changes (PAGES) program in Täiwan was initiated in March 1992 soon after the conclusion of the Asian IGBP

workshop held in New Delhi, India. Since lune 1992 various PAGES research projects have been funded by the National Science Council, Taipei (China). In addition, Quite a few projects which are related to the PAGES have been also funded by other programs, such as LOICZ, KEEP (a JGOFS project) and the South China Sea Project. A new integrated

program named Täiwan International Marine Past Global Change Study (IMAGES) has been

formed and funded.

The first four years (7992-7996) were considered a promotion period for the PAGES Program, aiming to establishing research facility, expertise and protocols. A competent research team of more than 20 principal investigators has been established. Research has been conducted on a wide array of materials, ranging from historical documents, corals, tree

rings, paleosols to lake and deep-sea sediments. To ensue proper analyses and further exploration of paleodata, collaboration among professional statisticians and geoscientists, in particulal, has been greatly encouraged. Funding for PAGES Program has been in the range of USD $500,000 per year, occupying 70-15qa 12

of the budget of the NSC's Geology Program.

Part of the funds has also come from the NSC's Marine Science Program. While stepping into the fifth year, requests for continuing support are under a more critical peer review based

upon previous accomplishments in the past four years.

The program has had a significant impact on Täiwan soft-rock geosciences. For the first time, more than a dozen geoscientists were teamed up in an integrated effort to gain a better understanding of the past environmental changes in Taiwan and its adjacent areas. A

team leader was elected every two years to coordinate the interdisciplinary effort and to promote dialog and intögradön among the various lines of research. Forums covering various progress reports have been held seasonally by the Global Change Centel, National Täiwan University. PAGES sessions have been scheduled in almost every annual Geological Society Conference and annual Ocean Science Meeting. Formal presentations of PAGES results in these and other international meetin$s have been an obligatory task for all the prin-

cipal investigators.

The PAGES team followed the recorunen-

dations of the IGBP PAGES (IGBP Report No.6, 1988) in emphasizing two temporal

streams: 1) the past 2000 years, 2) the last 150,000 years. The main endeavor in the beginning phase was to focus on the multi-proxy reconstruction of past environmental changes and data integration. Taking advantages of the availability of multiple archives in Täiwan and the adjacent areas, scientists obtained season, decade, century and millennium paleorecords from coral, tree-ring, paleosol,' lake and marine sediments. Further integration and exploration of these proxy data are being undertaken.

Areadjustment of the original PAGES research shategy has been made in collaboration with the new research foci as specified by the PAGES new workplan (IGBP Report N0. 28, 1994). The Taiwan area is sihrated in a key linking area bridging the northern and southern

hemispheres in the PEPII transect. The changing conditions of the Asia monsoon, west Pacific warm pool ENSO and marine circulation are sure to leave discernible reflections in the paleo-records of Taiwan. The PAGES team shives to reconstruct local records and to interpret the records regionally, if not globally.

To foster PAGES research in the monsoon Asia area, an international workshop was held in Taipei, Taiwan, Apil21-23, 1993. The theme was: the "High Resolution Records of Past Cli-

NATIONAT ACTIVITES mate from Monsoon Asia: the last 2000 Years and Beyond". The workshop was sponsored by the IGBP PAGES Program, and was financially co-sponsored by the National Science Councif Republic of China and the National Science Foundation, USA. More than 150 par-

ticipants from eight countries attended the workshop. A ftrll report of the workshop conclusions and recommendations was compiled

by Raymond Bradley (USA) as a pAGES Workshop Report (Series 93-1), and a summary was published in the EOS (74:601-603).

A selection of papers presented in the workshop was published in 1994 by the Teuestrial, Atmosphere and Oceanic Sciences in a special PAGES issue (TAO vol. 5, No. 3,p.349-442).

While the team members rejoice over a number of significant accomplishments, they acknowledge that there will be a continuing

struggle to ensure that Täiwan geoscientists

record of paleoceanographic changes in the southern South China Sea was reported by Chen et al (submitted).

can make further signi_ficant contributions to this global project. The initial success is only seen as the beginning of yet more promising progress in PAGES research in the areas of East

Century tro Decode Records from

loke Sediments

Asia monsoon as well as in the crucial linkage of the subtropical area in the PEP II hanseci.

Kuo-YrH Wg rr,ro PrHc-Mrr Lrw

The interlaminated dark and light-colored lake sediments obtained from several mountain lakes appear to reflect large-scale wet änd dry cycles over the past2,400 years (Chen et a1.,7993; Lou et al, 1996). The detected 450years periodicity is similar to that of the solar oscillation (Chen et a1.,1993). The Medieval WarmPeriod (1000-1300AD) and the Littlelce Age (1300-1850 AD) were recognized (Lou et aL,7996). These two epochs were also identified from palynological records of the Central Range (Liew et al., 1995). Pollen data in Taiwan imply the occurrence of a mid-Holocene climatic optimum during 7-3.7ka and a cooling period üxing3.7 -2ka (Liew et al., 1995).

A drastic floral change took place at about 4.8 ka (Liew andtluang, 1994).

Palynological data indicated that the veg-

Deportment of Geology, Notionol Toiwon University Dryro Drn-DurH Sxru lrro Cxrr-Tur.to Anrnun Cxrr lnstitute of Morine Geology ond Chemistry,

Notionol

Sun-Yot-Sen University

Kuo-Yrr Wrr Professor of Geology Dept. of Geology, Notionol Toiwon University 245

Chotshon Rood Toipei, TAIWAN, ROC Phone: 886-2"2691 1 43 Fox: 886-2-3636095 e-moil:

weiky@cc.ntu.edu.tw f

Documenting Post: Envircnmentol Chonges in Tqiwqn ond Adio(ent Arcqs Resufts

of

PAGES

Tqiwqn l$2-l9Pzb

Compiling and analyzing high-resolution records of past environmental changes from both historical and natural archives has been a major task of PAGES (Sheu et a1., 1994). Nthough the Taiwan PAGES Program only started in 1992, significant results have already appeared in various international and local periodicals. Some such results are summarized in this document.

etation distribution displaced vertically by

press). A higher terrigenous flux during the LGM, together with higher sea-surface pro-

ductivity, resulted in higher sedimentation rates and a larger accumulation of organic carbon and carbonates during the LGM. A carbonate preservation spike occurred at -12 ka, slnchronous.with the global preservation event of the Termination I (Wei et a1.,1996, Chen et al., in press). A 1.05 million-year

about 800 m between the last glacial and the Holocene, implying a 4.8'C change in temperature in the western foothill region of cenhal Täiwan (Huang et al, in press a). It is infened that in eastAsia, during the LGM (21 15.8 ka), the forest in the uplands became half open, while most of the lowlands were occupied by grassland. Less humid conditions than today prevailed in Taiwan during the LGM (Liew et al., submitted).

Millennium Records from Deep-seo Sediments

Äge{yn

Paleoceanographic studies (Wei et al., 7996,Huang et al., in press b, Wei et al., in press) indicate that the last glacial maximum (LGM) in the marginal seas around Taiwan was at about 14 -15 thousand years ago (ka) (in carbon-14 age), corresponding to a calibrated calendar age of 77-78ka. During the LGM, the axis of the Kuroshio shifted slightly to the east (Chen et a1.,1992). The summer sea-surface temperatures (SSTs) off the east coast of Taiwan were similar to today's at

about 29"C through the late Quaternary, whereas the winter SSTs (-22.5"C) were

B.P.)

$outh China Sea

w*ak

t4eäl( to moderate

rilnililllll

high weak

gradual

inqrease

low high

slrong

Taiwan Toushs Lake

abuüdanr

ry

Rare

-4.C

lower than today during the last glacial period (Chen et al., 1992).

The South China Sea witnessed a colder winter during the LGM: the SSTs were about 18"C, which is -6oC lower than today's winter SST (Wei eta1.,7996).The winter monsoon was considered to have been stronger during the LGM than today (Fig.1); consequently, ocean surface was better mixed and yielded

higher biological productivity (Wei et al., 7996,Huang et al., in press b, Wei et al., in

Moderäte

lntsgralion and

Conclssicn

lo $reak Weäk winter monsoon winler - sttong summet lrpnsoon

monsoon

- sttong

SUmmef

montoon

Mcderste aintea monso0n - werk lo moderale suülmet mo$söon

Slrong winlei rnonsooß - vlaak summet monsoon

!5.'t, 4n integrated mlnsoon history

int'erred from the proxy records in South China Sea and central Taiwan lake cores t'or the last 25 ,000 years . The marine and läke records are complementary and consistent, suggesting that the East Asian monsoon system has eaolaed t'rom an strengthened winter"monsoon during the.Iast g.Iaciation through a moderate to weak winter and summer *orroin, duving the deglaciation to in enhanced summer mlnsoon in the Holocene. (from Huang et al,, in press a).

IJ

Annuql to Seosonol Records from Tree-Rings Studies of tree rings of Taiwan fir allowed

wette{, intervened with the conspicuous Medieval Warm Period (1000-1300 AD) and the Little Ice Age (1300-1850 AD). Tree-ring data have also confirmed the effect of the Little Ice Age in the Taiwan alpine mountain region.

The fluctuation of humidity over the past 2400 years as derived fromlake sediments suggests that the recognized drylcold periods have coincided with major historical disturbance events in Chinese history. The precise calibration of coral thermometry based upon the [Sr/ Cal ratio has been successful, it now appears promising that an accurate reconstruction of sea-surface temperature for the past several thousand years can be made.

tended to a time span of greater than 100 first

years, covering the entire period since the

introduction of modem meteorological instruments to Täiwan.

for the reconstruction of the summer and winter temperatures of the alpine mountain area over the past 300 years (Flg. 1). It was thereby demonstrated that cold climate prevailed during the Little Ice Age (Tsou and Liu, in press). Further more, carbon isotopic variations in a 120-year-old Taiwan fir responded negatively to the mean May-October temperatures after stable growth with a coefficient of -0.46 %o oC-1 (Sheu et aI, 7996).

Monthly Records from Corqls

An empirical relationship between the [Sr/Ca] concentration ratio in corals vs. seasurface-temperature (SST) has been established in southern Täiwan. The temporal resolutionisbetter thana month, whilethe SSTcan be reconstructed with an error less than 0.1"C (Lee et al., 1995; Shen et al., inpress).Applying this paleo-thermometry, Lee et al'(1995) detected a 1-2oC warming for the winter 19821983, corresponding to the strong ENSO of 1982. The calibration effort will soon be ex-

Synopsis

Deep-sea sedimentary'records of the SouthChina Sea suggest that the winter monsoons were strengthened during the last glacial (25 -12 ka) while the summer monsoons were weaker than today's (Fig. 1). Ever since 12 ka, the winter monsoons have weakened, while the strength of the summer monsoons have gradually increased. An abrupt Younger DryasJike cooling event occurred from 11.3 to 10.3 ka radiocarbon years BP (Huang et al, in press a). Palynological data obtained from central Täiwan show consistent and complementary evidence of this although the Younger Dryas is not recognizable. The vertical shifting of vegetation in the deglaciation period suggests a warming of about 5"C in the subalpine area of central Täiwan. Pollen data in Täiwan imply the occurrence of a mid-Holocene climatic optimumduring 7- 3.7ka and a cooling period during 3.7 - 2ka. Over the past 2000 years, the climate has become warmer and

Kuo-Yrr,r Wrr

aro Prxc-Mu Lrw

Deportment of Geology, Notionol Toiwon University

Drvro Drn-Durn Sxeu mro Cx:r-Tur.rc Anrrur Cnrr lnstitute of Morine Geology ond Chemistry, Notionol Sun-Yol-Sen University For full references, pleose contoct:

Kuo-Ytr.r Wrr Professor of Geology Dept. of Geology, Notionol Toiwon University 245 Choushon Rood Toipei, TAIWAN, ROC Phone: 886-2-269,l I 43 Fox: 886-2-3636095 e-moil:

weiky@cc.ntu.edu.tw

I

PAGES CATENDAR (* Open meetings. All interested scientists ore invited to ottend)

*April 4 - 8, 1997, Lommi, Finlond - 'Circum Arctic Poleoenvironments'(CAPE) Synthesis Workshop: "Holocene Spotiol ond Temporol potlerns of environmentol chonge in the Arctic" Contoct: S. Hicks, Fox: (358) 8 553 l4B4; e-moil: sheilo.hicks@oulu.fi

I

*April - 18, 1997,lfuE[Vienno, Austriq - lnternotionol Symposium on 'lsotope Techniques in the Study of Post ond Current Environmentol Chonges in the Hydrosphere ond the Atmosphere' Contoct: Ms. T. Niedermoyr, Conference Service Section - e-moil: niedermo@odpol.ioeo.or.ot

I

l4

*Aprif 2l - 25, 1997,Yienno, Auslriq - Europeon Geophysicol Society - See especiolly Session OAl3, "Climote voriobility observotion ond modelling", sub-session "Reconstruction of post climotes through

I

Modelling ond Observotions" Contoct: G. Romstein, e-moil: romstin@osterix.socloy.ceo.fr

I

*Moy l0 - 15, 1997, Coslelvecchio Poscoli, ltoly-

poleoclimote onolysis Contoct: Josip Hendekovic, ESF, Phone: +33 3 88

I

Jufy 6

-ll,

Poleoclimote modelling ond onolysis, Quoternory

767135; Fox: +33 88 36 6987; e-moil: euresco@esf.org

1997, Hoborl, Auslrolio

- SCAR/GLOCHANT AND IGBP/PAGES Worshop on lhe "lote quoternory sedimentory record of the ontorctic ice morgin evolution" (ANTIME) Conloct: lon Goodwin, Phone: +61 3 62267544, Fox: +6,1 3 6227 7650; emoil: ion.goodwin@ontcrc:utos.edu.ou

*August 24 - 30, I997, Krosnoyorsk, Russio - Siberion Tronsect Workshop on "spotiohemporol dimensions of High-Lotitude Ecosystem Chonges" Contoct: V.A. Koptyug, Fox: (Z) 3832 35 4846; e-moil: evog@ifor.krosnoyorsk.su

I I

PAOES PAST

GLOBAT CHANGES

PAGES Core Proiect Office

Börenplotz 2

I

CH-301 Bern, Switzerlond Phone: +41 31 3]2 3]33

Fox:

+4] 31 312 3168

E-moil: poges@ubeclu.unibe.ch

WWW:http://www. ngdc.nooo. gov/ poleo/poges. html

Newsletter Editor: Fronk Oldfield Prinied on recycled poper

14

*August 28 - September 2, 1997, Heiligkreulz/Riedlingen, Germony - "seventh lnternolionol

Symposium on Poloeolimnology"

5ll

643 3667; e-moil: merkt@gotel .bgr.d400.de.

This Symposium is followed by o scientific celebrolion of the 80th birthdoy of Herbert E. Wright, Jr. ol Wengen, l1) Switzerlond (Sept.

Contoct: B. Ammonn, Fox: (4lJ 3l 332 2059 Contoct:J. Merkt, Fox {49)

8

I

September 7

- 13,

1997, Johonnesburg, Soulh Africo-Third Symposium of Africon Polynology.

Contoct: Ann Codmon, University of Witwotersrond, e-moil: l06coo@cosmos.oc.zo

*April 79 - 23, I 998, UK - "PAGES Open Science Meeting", Royol Hollowoy University of London, UK. Contoct: Fronk Oldfield, PAGES CPO Switzerlond, Fox: +41 3l 312 3l68; emoil: oldfield@pogeigbp.unibe.ch

I I

*IYloy

l6 - 23, 1998, Iorshovn, Foroe lslonds

Contocf:C.Coseldine,UniversityofExeter,UK-Phone: e-moil:

I

- "Environmentol Chonge in Atlontic lslonds"

+441392263347;Fox +441392263342;

c. i.coseldine@exeter.oc.uk

*August 3 - 11,1999, Durbqn, South Africo - "The Environmentol Bockground to Hominid

Evolution

in Africo", INOUA XV lnternotionol Congress, Internotionol Congress Cenhe Durbon Contoct: MorgoretAvery, Phone: +27 21 243 330; Fox: +27 21 246 Zl6; e-moil: movery@somuseum.oc.zo

PAOES PAST GTOBAL

CHANGES

sctENTrFtc HlcHLtcHT Greqt Bqrrier Reef 'Climqtic Optimum'qt 5,800 y BP

M.K. Gagan, L.K. Ayliffe,

S.

Anket, D. Hopley, M.T. McCulloch,

Parts of North America and Europe were warmer during the mid Holocene while a shonger monsoon produced warmer/wetter cljmates in northern Africa and central Asia (COHMAP, 1988).

The nature of the mid Holocene 'climatic optimum' is less clear for the southern hernisphere; although recent work on ice cores from

high-altitude hopical glaciers in Peru indicates that air temperatures were warmer from 8,000 to 5,000 Y BP (Thompson et al., i995). At the same time, sea surface temperatures (SSTs) along the coast of Peru may have been warmer and less variable suggesting that the El Nino - Southern Oscillation (ENSO) may have been weak, or absent (Sandweiss et aI.,1996).

The new PAGES-CLIVAR initiative on Annual Records of Tropical Systems (ARTS) promotes the synthesis of paleoclimatic, instrumental, and modeling data to improve our understanding of tropical climate variability. An importantgoal of theARTSinitiative is to reconstruct climate systems during ancient periods with different

background climates and forcings.

Toward this goaf we have applied a multi-tracer approach to a fossil coral from the windward side of Oqpheus Island, cenhal Great Banier Reef, to reconstruct climatic conditions in northeastAushalia during one century of the mid Holocene (Gagan et al., 1995). At Orpheus, well-preserved massive Porites micro-atolls have been cored to reveal 100 years of continuous coral growth. The largest colony, forwhich preliminary data are presented, has a conventional radiocarbon age of 5,800 Y BP. The fossil coral data presented here have been calibrated via proxy data for modern corals growing adjacent to the fossil coral colony.

Examination of the coral IIV fluorescence, indicating the intensity of runoff from mainland rivers (Isdale, 1984), suggests that monsoonal rainfall during this century of the mid Holocene was much less variable than tod ay (see Figure). The intensity of UV fluorescence for modern corals analogues varies from 0 to 700 fluorescence units in response to cycles of drought and flood, In contrast, fluorescence in the mid Holocene coral is restricted to 100 to 300 units. The results indicate that droughts and floods were rare during this century of the mid Holocene.

In order to further verify the W fluorescence record) we made high resolution measurements of the coral Sr/Ca to examine SSTs (Beck et a1., 7992) and E18O to document the seasonal dynamics of monsoonal rainfall (Gagan eta1.,7994;McCulloch et al., 1994). The calibrated coral SrlCa-SSTs for years 80 to 96 indicate that mid Holocene SSTs were 1oC warmer than those of the last two decades.

If these elevated SSTs represent regional warming in the westem Pa-

P.J.

Isdale, J.M.A. Chappell and J. Head

cific, higher evaporation rates and persistent summer cloudiness should follow. Note that the surnmer SSTs are closely confined to a mean temperature of about29.soc, and rarely exceed 30"C. This is the situation today further north near New Guinea where high evaporation rates produce persistent summer clouds whichblock incoming short-wave radiation, resulting in a negative feedback on further increases in SST. Persistent clouds also tend to damp fluctuations in summer SSTs. The warm, consistentsummer SSTs indicatedbythe coral Sr/Ca reinforce the UV fluorescence in suggesting that summers in the Great Barrier Reef were typically cloudy with moderate monsoonal rainfall.

The 16-year SrlCa-ö18O record also provides a rare opportunity to look for evidence of individual ENSO events. Contemporary ENSO-induced droughts in northeast Australia coincide with cool winter SST anomalies of at least 1-2"C. In addition to providing information about SSI coupled measurements of coral Sr/Ca and 8t8O make it possible to determine seawater E18O by removal of the temperature component of the coral ö18O signal. Seasonal changes in seawater ö18O, as registered by the coral, provide a good measure of the magnitude of river runoff and prgcipitation. The coral record spans the three years that we perceived to be the driest in 100 years, based on vsual inspection of the coral UV fluorescent bands (years 82-85 in lower panel). Despite this period being fairly dry, the winter cooling associated with this 'drought' is negligible, and certainly not indicative of ENSO. This record is admittedly short, but the Srl Ca and 8180 data have now been extended to nearly 30 years with no sign of winter cooling or drought indicative of ENSO. Täken together, the evidence suggests that this century ofthe mid Holocene was marked by warmer SSTs, more dependable monsoonal rainfall, and possibly a weaker ENSO, The persistence in time of the apparent weakening of the mid Holocene ENSO is unknown but, if real, the ramifications of a weakened ENSO should be evident in high-resolution palaeoclimate records throughout much of the tropics.

Text submitted by:

Dn.

Mtcxlrl K. Glolrr

Environmentol Geochemistry Group Reseorch School of Eorth Sciences Austrolion Notionol University Conberro, A.C.T. 0200, Austrolio Phone:

+61 6249 5926

E-moil: michoel.gogon@onu.edu.ou

References: Beck, J.W., R.L. Edwords, E. lto, F.W Toylor, J. Recy, F. Rougerie, p Joonnot ond C Henin

rotios. Science 257: 644-647.

'l

992. Seo-surfoce temperoture from corol skeletol stronfium/colcium

COHMAPMembers, I988.Climoticchongesof thelost'l 8,000yeors: observotionsondmodel simulotions.Science24I:I043-I052.

Gogo.n, M.K., A.R. Chivos ond PJ. lsdole 1994. High resolution isotopic records from corols using oceon temperoture ond moss-spowning chronometers.

Eorth Plonet, Sci. Lett, l2l : 549.558.

Gogon, M.K., L.K.ayliffe, M.T- McCulloch,.S. Anker,^D. Hopley ond PJ. lsdole 1995. SrlCo ond ö,80 in Greor Borrier Reef corols ond ENSO dynomics or 5.8 ko BP Americon Geophysicol Union Foll Meeting, EOS Supplämentory lssue 76:316. lsdole, P 1984. Fluorescent bonds in mossive corols record centuries olcoostol roinfoll: Noture 310:578-579.

McCulloch,.M.T., M K. G.E. Mortimer, A.R. Chivos ond PJ. lsdole 1994. A high-resolution Sr/Co ond ErsO corol record from the Greot Borier Reef, ,G^lg^on, Austrolio, ond the 1982-1983 El Nifro. Geochim. Cosmochim. Acto 5g: 2747.2754. ,1996.

Sondweiss, D H , J B. Richordson lll, E.J. Reitz, H.B. Rollins ond K.A. Moosch, Geoorcheologicol evidence from Peru for o 5,000 yeors Bp onser of El Nino.

Science 223: l53l-1533 Thompson, L.G', E M.E. Dovis, PN. Lin, K.A Henderson, J. Cole-Doi, J.F. Bolzon ond K.B. Liu, ,Mosley-Thompson, ice core records from Huoscoron, Peru. Science 269: 46-5Q.

'l

995.

Lote

glociol stoge ond.Holocene hopicol

l5

PAOES PAST GTOBAL

CHANGES

sclENTrFrc HTGHUGHT GREAT BARRIER REEF SSTs

AND RUNOFF AT 5,8OO y

Annuol Runoff ot 5,800 y

BP

BP

Sl:/Cq , ör8O (timeslice,Blqnd C)

SSTs

ond Runoff ot 5,800 y

BP

-5.5

o30 :-

-5.0

F

q28 o 326

:'E C)

o_

-4.5

o

@

@

rJ)

-4.0

Yeorly lncremenl

85

A) 100-year record of annual UV fluorescence for the 5,800 y BP Porites miuo-atoll from Orpheus Island, central Great Barrier

Reef

.

- L80' indicates 1,6-year interaal chosen for coupled SrlCa and 88O measurements..

B) 16-year record of coral Sr lCa (black line) and ü8O aalues (grey line with dots) conuerted to SST. The difference between the SrlCa and 88O curaes represents the intensity of monsoonal runoff .

Horizontal lines show the mean winter and summer SSTs t'or L970-1994.

C) Coral 88O residuals conaerted to show the magnitude of runoff from the palaeo-Burdekin Riaer.

Bar labelled 'Srf Ca

l6

M